Using a forward genetics approach, a team of Biosciences researchers revealed that the enzyme hexokinase (HXK1), which is involved in sugar metabolism in organisms ranging from bacteria to plants to humans, is necessary for the regulation of photosynthesis and metabolism in the green alga Chromochloris zofngiensis. Kris Niyogi, a faculty scientist in Molecular Biophysics and Integrated Bioimaging (MBIB), was senior author on the paper, published in Nature Communications Biology.
The unicellular green alga Chromochloris zofingiensis has the ability to shift metabolic modes from photoautotrophic (synthesizing food using light as energy source) to heterotrophic (obtaining food and energy from exogenous sources) in response to carbon source availability in the light. It also has the capacity—under certain conditions—to produce high amounts of commercially relevant bioproducts: notably, the ketocarotenoid astaxanthin, used in feed, cosmetics, and as a nutraceutical, and triacylglycerol (TAG) biofuel precursors.
Understanding how photosynthesis and metabolism are regulated in algae could, via bioengineering, enable scientists to reroute metabolism toward beneficial bioproducts for energy, food, and human health. To that end, Berkeley Lab Biosciences researchers used C. zofingiensis as a simple algal model system to investigate conserved eukaryotic sugar responses, as well as mechanisms of thylakoid breakdown and biogenesis in chloroplasts.